Treatment of hydrocarbon oils



Patented Oct. 28, 1941 TREATMENT or nrnaooamson ons Arthur R. Goldsby', Beacom'N. 1.. and Karl Korpi,

Redondo Beach, Calif., assignors to The Texas Company, New York, N. Y., a corporation of Delaware No Drawing. Continuation of application Serial No. 148,979, June 18, v193'7. This application July 29, 1939, Serial No. 287,250

6 Claims. (01. 196-10) This invention relates to' the treatment of hydrocarbon oils and has to do particularly with the treatment of hydrocarbon oils with sulfuric acid, while in the presence of a substantial amount of. isobutane.

The hydrocarbon oils to be to the invention are those commonly subjected to acid treatment for the removalof impurities, such as gasoline and naphtha. I

An object of the invention is to purify theoil by removal ofundesirable constituents and at the same time to obtain improvement in the quality of the oil by interaction of the isobutane. with unsaturated constituents of the oil to produce.

new ingredients having desirable properties for improving the-characteristics of the treated oil. In the refining of hydrocarbon oils, such as those of petroleum origin, it iscommon practice to subject the oils to the action of sulfuric acid to remove the unstable color, gum producing and carbon forming bodies. It has been found that an advantageous method of operation is to treat the oil with sulfuric acid in the presence of isobutane in excess of that naturally occurring in the oils.

In practicing the invention the isobutane is incorporated into the oil and the mixture then contacted with the treating reagent. The amount of treated according Pressures from atmospheric to 150 pounds may be used, depending on the amount of isobutane and vapor pressure of the original oil. It is necessary to use only suflicient pressure to maintain the mixture in the liquid phase. Any well known or preferred method of contacting the mixture with the acid may be used.- The amount of acid may vary between about 3 and 50 pounds per barrel of oil and preferably about 5 to pounds per barrel.

As an example of the operation of the invention, a cracked distillate. having an unsaturated hydrocarbon content of about 25% was treated with 5 pou'nds'per barrel of 94% sulfuric acid. The acid treated product was neutralized and redistilled ,to the end point of the original oil. A loss of about 5% and a decrease in the antiknock of I about 3 points occurred. By treating a sample of the same distillate in substantially the same manreagent may be the same as that customarily used for refining purposes, although better results are often obtained by using a somewhat larger amount. The temperatures employed. may be those commonly used in'the particulantreating method. In acid treatment, low temperatures, for example 100 F. or lower, are preferred. It is preferable to use sufficient pressure to maintain the oils in the liquid phase, although in the case of the lower boiling oils vapor phase treatment may be used. Pressures of 50to 500 pounds are ordinarily sumcient and ordinarily about 75 'to 150 pounds aresatisfactory.

In carrying out the operation of the invention with sulfuric acid, a strong or concentrated acid up to 100% has been found satisfactory. We pre-. fer to use about 94% acid. The temperature may vary from about 0 to 100 F. and preferably about 70 to 90 F. The amount of isobutane added will vary according to the charge stock. As a rule the maximum amount of isobutane, in mols, will be approximately double the quantity of unsaturated compounds, in mols, in the charge stock. For a cracked distillate a beneficial effect may be obtained with as little as 5% by weight of isobutane. For a greater increase in yield and octane value as high as 100% by weight may be used.

ner except 25% of isobutane was added to the distillate prior to treating, a substantial gain in yield occurred and the antiknock value increased'about 2 points.

, The improvements are believed to be due to interaction of the oils with the isobutane to produce alkylated products.

This application is a continuation of pending.

application Serial No. 148,979, filed June 18, 1937.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. A process for the treatment of crack'ed hydrocarbon distillates of the class of gasoline and A naphtha, which comprises contacting the cracked distillate with concentrated sulfuric acid'in the presence of added isobutane in amount'larger than the quantity of. unsaturated compounds originally present in said-distillate, the concentration of the acid and the amount of isobutane being such as to effect alkylation of the isobutane with normally liquid olefins originally present in the cracked distillate whereby the distillate is refined and the yield of treated product is great-v er than normally occurs without the presence of the added isobutane.

2. A process according to claim 1 in which the concentration of the acid is about 94 to 100%.

3. A process according to claim 1 in which the temperatureis about 0 to 100 F.

4. A process according to claim 1 in which'sumcient pressure is used to maintain theadded isobutane in the liquid phase.

5. The process of alkylating a normally liquid cracked naphtha fraction to increase its antiknock value, which comprises treating the said cracked naphtha fraction with added isohutane in amount substantially greater than the quantity of unsaturated compounds present in said fraction in the presence" of concentrated sulfuricacid duce liquid 'alkylation products.

under alkylating conditions, whereby isobutan'c l0 6. The process according to claim 5, in which the said cracked naphtha traction and the said added isobutane are substantially devoid of normally gaseous oleflns.

ARTHUR R. GOLDSBY. KARL KORPI. 

